fix(paper-extraction): never fabricate DOIs for no-DOI bib entries

[cailmdaley]

Problem

The paper-extraction DOI resolver fuzzy-searches Crossref/ADS by title for any bib entry lacking a doi:/eprint: field, and accepts the top hit if a SequenceMatcher title ratio clears 0.55. Two failure modes let it attach wrong DOIs — a direct traceability violation, since a wrong DOI silently points astra validate --verify-evidence at the wrong paper:

1. "in preparation" entries (no DOI exists yet) match unrelated journal articles. On the UNIONS B-modes bibliography, Papers III & IV (goh.etal26, guerrini.etal26) both got 10.1111/j.1365-2966.2010.17430.x — an unrelated 2010 MNRAS paper.
2. ASCL software records match by subtitle collision. treecorr15 (TreeCorr: Two-point correlation functions, archivePrefix=ascl) got 10.2172/6401879 — a 1978 DOE OSTI report subtitled [Two-point correlation functions], which cleared the 0.55 gate (similarity ≈ 0.63).

The ADS fallback path had no similarity gate at all.

These were surfaced by a citation-audit dry-run: workers were handed the wrong paper to verify against and could not recover. This is not LLM hallucination — it's a deterministic programmatic search with too-loose acceptance.

Fix

Principle: traceability over coverage — a flagged miss (doi: null, surfaced for human review) is strictly preferable to a fabricated hit.

• classify_unresolvable() short-circuits entries with no DOI to find — unpublished (in prep/submitted/to appear/in press/forthcoming in journal/note/howpublished), ASCL software records (archivePrefix=ascl or ascl: eprint), or entries with no publication metadata — to doi: null plus a needs_human tag. These are never fuzzy-resolved.
• Raise the fuzzy title gate 0.55 → 0.80 AND require a first-author surname match, on both the Crossref and ADS paths (the ADS path was previously ungated).
• Unresolved entries carry needs_human in the citations: block so a downstream consumer or human can act on them.

Verification

Against the UNIONS B-modes bibliography (79 entries):

• The four in-prep companions and the TreeCorr ASCL entry that previously got phantom DOIs are now flagged (in_preparation / software_ascl); none are fuzzy-resolved.
• All published entries (real doi:/eprint:) still resolve unchanged.
• The exact phantom collision (TreeCorr… vs the 1978 DOE report) now scores 0.63 < 0.80 — rejected by the gate even independent of the no-DOI guard.

Adds tests/test_paper_extraction_doi.py (15 cases: classifier, author matcher, title gate). No new lint debt (E501 count unchanged).

🤖 Generated with Claude Code

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❌ Eval Results

Metric	Value
Score	0.00
Build complete	❌
Cost	$0.00
Turns	0
Duration	0s
lightcone-cli	0.3.7.dev3+ga5e767ffc (a5e767ff)
Results	Download

Graders

No grader results

Full output

16:24:12 lightcone.eval.build Building lightcone-cli wheel from /home/runner/work/lightcone-cli/lightcone-cli ...
16:24:17 lightcone.eval.build Built lightcone_cli-0.3.7.dev3+ga5e767ffc-py3-none-any.whl (commit a5e767ff)
16:24:20 lightcone.eval.harness Trial build-snae-0 failed: Failed to create sandbox: Invalid credentials
Traceback (most recent call last):
  File "/home/runner/work/lightcone-cli/lightcone-cli/src/lightcone/eval/harness.py", line 112, in run_trial
    sandbox.create()
  File "/home/runner/work/lightcone-cli/lightcone-cli/src/lightcone/eval/sandbox.py", line 149, in create
    self._sandbox = self._daytona.create(
                    ^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/lightcone-cli/lightcone-cli/.venv/lib/python3.12/site-packages/daytona_sdk/_utils/errors.py", line 206, in sync_wrapper
    process_n_raise_exception(e)
  File "/home/runner/work/lightcone-cli/lightcone-cli/.venv/lib/python3.12/site-packages/daytona_sdk/_utils/errors.py", line 139, in process_n_raise_exception
    raise create_daytona_error(
daytona_sdk.common.errors.DaytonaAuthenticationError: Failed to create sandbox: Invalid credentials
  snae trial 0: score=0.00 error: Failed to create sandbox: Invalid credentials

lightcone-cli: 0.3.7.dev3+ga5e767ffc (HEAD a5e767ff)
ASTRA: 0.2.9

  Eval Results: Scores  
┏━━━━━━┳━━━━━━━━━━━━━━━┓
┃ Task ┃     Score     ┃
┡━━━━━━╇━━━━━━━━━━━━━━━┩
│ snae │ 0.00 +/- 0.00 │
│      │  pass@k: 0%   │
│      │   1 errors    │
└──────┴───────────────┘

   Eval Results: Cost &   
         Duration         
┏━━━━━━┳━━━━━━━━━━━━━━━━━┓
┃ Task ┃ Cost / Duration ┃
┡━━━━━━╇━━━━━━━━━━━━━━━━━┩
│ snae │      $0.00      │
│      │       0s        │
└──────┴─────────────────┘

Total: 1 trials, $0.00, 0s

Results saved to: eval-results/build-a5e767ff/results.json

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Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	lightcone-cli	e943952	Commit Preview URL Branch Preview URL	May 30 2026, 04:24 PM